Frame for producing casting flasks

ABSTRACT

A frame for producing casting flasks is provided with pin-andsocket means for locating fixedly within the frame a model to be impressed within a flask.

United States Patent [191 Nelson June 26, 1973 1 FRAME FOR PRODUCING CASTIN FLASKS Y [76] Inventor: Alden T. Nelson, 12413 First Avenue, South Seattle, Wash.

[22] Filed: June 11,1971 [21] Appl.No.: 152,271

[52] US. Cl 425/175, 249/91 425/128 [51] Int. Cl. B291: 1/00 [58] Field of Search 425/175, 176, 124,

[56] I References Cited v UNITED STATES PATENTS 3,372,448 3/1968 Ne'ys.'....'... 249/91 X Hubert 249/94 382,088 5/1888 1,271,579 7/1918 Kavanagh 425/176 X 2,604,660 6/ 1952 K arns 249/91 X 3,109,201 11/1963 Dulmage 249/94 FOREIGN PATENTS OR APPLICATIONS 7 570,536

211959 Canada 249/93 Primary Examiner-H. A. Kilby, Jr. Attorney-Ford E. Smith [57] ABSTRACT A frame for producing casting flasks is provided with pin-and-socket means for locating fixedly within the frame a model to be impressed within a flask.

5 Claims, 4 Drawing Fi'gnres FRAME FOR PRODUCING CASTING FLASKS I SUMMARY OF THE INVENTION Various types of flask frames or boxing frames are used to form resilient flasks having a model therein which, when removed, leaves a molding cavity. It is customary to mount the model on a sprue former so that the finished flask will include a sprue passage for the introduction of cavity reproduction material such as wax, for example. Ordinarily the model on its sprue former is only loosely placed in the boxing frame and;

is easily dislodged or moved during the filling of the frame with the impression material of which the flask is to be formed. The main object of this invention is to provide apparatus to fixedly locate the model and its sprue-former with respect to packing the frame and the solidifying of the impression material. It is also an important object of this invention to arrange such appara- DESCRIPTION OF THE DRAWINGS I FIG. I isa perspective view of a flask frame embodying the sprue holder of this invention;

FIG. 2 is a cross-sectional view of an assembled flask showing -a rubber mold formed about a model supported by thesprue holder;

FIG. 3 is a perspective'view of the screw sprue holder; and v FIG. 4 shows an alternative sprue holder.

DETAILED DESCRIPTION f A flaskbody or boxing-frame 10, formed of 16, 18, provides the pattern chamber 20to flrst'receive the model 22 on sprue '24; and then to receive and be filled a mass of uncured rubber or the like. Model 22 is here shown as a'pattern ring 26 having an ornamental design pattern element 28 to'be reproduced. Sprue or shank 24 is attached to thepa'ttern ring 26. Screw 32 passes through wall 14 and in its inner conical end 34 has socket 36'to receive the end of sprue 24.

When model 22 is properly positioned in pattern chamber 20 and seated in socket 36, as shown in FIG. 1, the fixed location of socket 36 and cone 34 in the middle of the inner surface of wall 14 insures that the model is correctly centered in chamber 20.

The pattern model 22 is then suitably coated, as also are the chamber walls, with a suitable release or parting agent. Then the flask frame 10, resting on a base plate 40, is filled with the natural or synthetic rubber or rubber-like impression material which ultimately forms the flask 42. Cover plate 44 is applied. Clamps such as 46 are engaged to firmly hold the frame and plates assembled while vulcanization or polymerization takes place.

When it is desired to remove-thesolid but flexible flask 42, including the model, from the frame 10, the

model, to aid the parting of the rubber-like flask therefrom, screw 32 may be turned to inwardly project the socket 336 and thereby apply pressure to shank 24 and the model 22. To remove the flask 24 from the frame 10, screw 32 is retracted to draw the cone 34 into wall 14 and disengage socket 36'from the end of sprue or shank 24. Thereupon the flask 42 may easily be extruded from chamber 20 without hindrance.

The removal of the pattern model from the rubber flask 42 is accomplished in the usual manner by cutting andparting the flask so as to separate it into two distinct but matching parts. It will be found that cone 34 has modelled a funnel-like mouth leading to a passage formed by stem 42. The mouth is provided for the filling of the pattern cavity with melted wax in the production of an identical duplicate model of the original pat-' tern 22.

. In the alternative construction of FIG. 5, the sprue former shank or stem 50 has a flared, conical base 52 theman appropriately liberal construction and apply ing the doctrine of equivalents, will be deemed protected hereby.

' What is claimed is:

1. In combination; f

a open ended boxing frame having all inner wall surfaces parallel to the axis of the cavity of said frame to receive rubber-like-impression material;

a screw member passing through a wall of said boxing frame into its cavity;

a sprue-former and a model to be reproduced located wholly within said cavity; and

I inter engaged pin-and-socket means within said cavity joining said sprue-former and said screw to fixedly-support said sprue-former and model on the axis of said screw within the frame cavity.

2. Structure according toclaim 1 in which the socket is carried by the screw member and the sprue-former includes a pin seating in said socket.

3. Structure according to-claim 1 in which the socket is carried by the sprue-former and the screw member former includes a conical base having the socket axially located therein. 1

I i i 4 

1. In combination: a open ended boxing frame having all inner wall surfaces parallel to the axis of the cavity of said frame to receive rubber-like impression material; a screw member passing through a wall of said boxing frame into its cavity; a sprue-former and a model to be reproduced located wholly within said cavity; and inter engaged pin-and-socket means within said cavity joining said sprue-former and said screw to fixedly support said sprueformer and model on the axis of said screw within the frame cavity.
 2. Structure according to claim 1 in which the socket is carried by the screw member and the sprue-former includes a pin seating in said socket.
 3. Structure according to claim 1 in which the socket is carried by the sprue-former and the screw member includes a pin seating in said socket.
 4. Structure according to claim 1 in which the sprue-former comprises a pin and the inner end of the screw member is conical and has a central socket to receive said pin.
 5. Structure according to claim 3 in which the sprue-former includes a conical base having the socket axially located therein. 